Technical Field
Embodiments of the subject matter disclosed herein relate to turbochargers. Other embodiments relate to tip clearance of a turbocharger turbine.
Discussion of Art
Turbochargers may be used in an engine system to increase a pressure of air supplied to the engine for combustion. In one example, the turbocharger includes a turbine, coupled in an exhaust passage of the engine, which at least partially drives a compressor via a shaft to increase the intake air pressure. Exhaust gas passing through the turbine rotates the blades of a turbine disc mechanically coupled to a compressor wheel through the shaft. The performance of the turbine disc assembly may be achieved by a turbine blade tip clearance between the rotating turbine blade and a stationary turbine shroud. The tip clearance may be set during manufacturing to provide a desired turbine disc performance, such as a maximum turbine RPM, pressure drop, or the like.
Turbine blade tip growth, as well as turbine shroud geometry changes, may occur during turbocharger operation and result in varying tip clearance between the turbine blade and shroud. As tip clearance increases, turbine efficiency may decrease. Tip contact between the turbine blade and shroud may result in degradation of the associated turbocharger components. It may be desirable to have a system and method that differs from those that are currently available.